Method and means for determining the direction of sounds



S Ha 5 w. Mil A Q l saw. 11, 1923.

E. M. vow Ho'RNaQsTEL' ET AL IBTHDD AND [SANS FOR DETEMINIKQ TH! DIRECTION 0! SOUID! rum Ilaich I. 1820 2 huh-Shut 1 7:? wafer Moritz var: janzbaskl W mum, "My

Sept. 11, 1923.

v v E. M, VON HORNBOSTEL 51' AL 'I'ITHOD AND BEANS FOR DETERMINING TH! DIIBGTIOI O! SOUNDS m lamb ai 19:0 2. Shntl-$h|at 8 7:: wafers En'cb MomYz van Harnbosiel flax h'erfbez'Jn-er; 3- $1 0 r22 eya:

Patented Sept. 11, 1923.

UNITED, s'rAr-Es PATENT ors cn;

BBIC'H HOP-1T2 VOI' EOBHBOSTEL-OF QTEGLITZ, BEE-L1H, ARI) m v 33T- 0F BEBLIH, 6W.

mxon AND we FOB DETERMINING THE DIRECTION OI SOUNDS.

Application filed Batch 8, 1820. Serial Io. 364,3.

enmxn U'ICBEB TEE PEOYISIOKB 01 m ACT OF MARCH 3, 1921, 41 STAT. Ii, 1818.)

To all whom it may cmicem:

Be it known that we. Enron Monrrz vox HORNBOBTZL and Max Wmnmmnn, citizens of the Austrian Republic and of the Czechoslovakian Republic, respectively, residing at Steglitz, near Berlin, and Berlin, Germany, respectively, have invented certain new and useful Improvements in Methods and Means for Determining the Direction of Sounds,

(for which we have filed applications in Germany, July 6, 1915, atent iued Sept. 28, 1920, No. 301,669; ustria, November 17-,

1915; Hungary, November 16. 1915; Japan,

September 9, 1920; Canada, Se tember 14, 1920; Belgium, June, 28, 192 pain, September 1, 1920; Holland, November 14, 1919; Holland, September 18, 1920; Denmark, March 15, 1920; Norway, March 22,

1920; Itslg, June 26, 1920; Chile,- October 23, 1920; rgentina, October 20, 1920; England, February 5, 1920; Sweden, November 14, 1919; France, January 23, 1920), oi which the following is a specification.

Our invention refers to the determination of the direction of the approach of sounds and more especially to a method for renderi'ng such determination more exact. The invention further comprises certain means for aging such method into practice.

e have ascertained that the perception and determination of the direction of sounds is dependent on the absolute difi'erence of time consumed by the sound in reaching the ears of the observer. According to the presont invention, we utilize the well-known faculty of the ear to discern directions, for incressin the exectitude in the determination of the 'rection of sounds received by aid of special receivers, by converting a lateral impression of direction into a central one.

This may be effected for instance by nrranging the receivers, such as ft noel-shaped mouthpieces or microphones, at the ends of a. carrier capable of being 1n a predetermined plane about its center. Supposing now the sound to be mad as coming from the ri ht or the left, then the carrier or receiver ssis is turned about its central axis, the observer thereby getting the impression that the sound chances its direction as the carrier is turning. The CAIIIB! can be set in such a position that the observer imagines the sound to arrive neither from sound and the two receivers are equal, or in other words, where the vertical erected in the center of the line connectin the two recelvers meets the source of sons In thi case the angle of deflection of the carrier from its zero for the deflection of the sound.

Apparently the turning of the carrier or receiver base may be efi'ected' by causing the observers stand such as a vehicle or a vessel to turn as a whole. But when the lateral impress on of the direction -would be converted into a central one, the whole shi must be turned, which is a very difii t matter in a rou h seaand requires changin the course 0 the vessel.

contrsdistinctionithereto the method according to the in converting a central one without the observers stand bein turned. f

is mode 0 proceeding' is of cial importance for nautical pu "w asmuch as the course of a. ship u n no more be changed in order to determine the direction of sound.

In the drawings aflixed to this specification and forming a part thereof two modificstions of a receiver instrument according to the present invention are illustrated. In the drawings Fig. 1 is a pers strument as a who true direction of ive view of the ineilwlnle Fig. 2- is a plan is owing a modified arran ent of the sound receiving means.

T hi l igs. 8 and 4 show each partly in side elevation partly in vertical section a third and fourth modified arrangement of the sound receiving means;

Referring to Fig. 1, a, a are the sound receivers and b is a horizontal carrier capubis of turning shoot a vertical axis It on a tripod t and having the receivers a fixed to its ends at an even distance from the said: axis. r is a scale allowing t' ascertain the deviation from zero of the carrier and I is I.

resent invention consists teral impression into I position offers a measure which can be turned with their base about its middle axis. The receivers e, e are con- Fig. 2.

differs from vided that suitable receivers areemployed in a well-known manner. The soun is conand the carrier is constructed accordance ducted from the receivers to the bpbserveir; witi the velocity of sound in the respective ea for 'nstance b aid of two to scan IB mm. f i l' l th, 3 It will be understood by those skilled in The observer may take any desired posithe art that the adjustment of the paths of {i l tiv l t th Zero iti d d travel and the ad ustment of the tunes of not follow the movements of the receivers. travel are equivalent phrases as the com- The plane in which the carrier is turning parlson to be made is that of the times of may be horizontal or vertical or inclined. In rrival of sounds at the two ears of the the case of a carrier turning in a vertical observer and these'tunes may be synchrpplane the elevation of the direction of sound tilled, for exam;- e, by adyustmg the reht-r relatively to the horizontal can be determintive lengths of the paths according to ured. By combining a horizontal and a vertlcumstunces. cal carrier in one instrument two observers We claunzmay simultaneousl determine the lateral 1. That method ofi determining the d1- deviation and the e ovation. rect on of sound by the aid of apparatus The lateral impression of direction may having tworece vers spaced apart, faced m further be converted into a central one by the same direction, and arranged vvhereby either altering the distance of sound transeach will receive the same sound with submission from one receiver to the ear constantially the same freedom from obstrucnected therewith or by altering the distance tion, and having individual connections between both receivers and the respective therefrom to the ears of the observer, which ears connected therewith in an opposite consistsin settin said apparatus 1n an imsense, and measuring. the diti'erence. A detlal position, wi the obser ver assuming a vice adapted to carry this latter method into definite and fixed orientation relative to practice is illustrated diagrammatically in 881d position, and thereafter ad usImg sanl apparatus so that the sounds from the receivers will be brought simultaneously to the observers ears and the impression of lateral directions will be converted into an impression of central direction without chan 'ng the orientation of the observer.

2. The method of determining the ditelescope for adjusting it in its zero osition m, m are two stationary receivers and n and o are separate tubes serving to conduct the sound from said receivers into the ears of the observer. The tubes n and o are connected with the receiver tubes 8, a by aid of tubular sleeves p, p adated to be axially dis laced thereon, the tn 8, a being 61- vi ed so that the increaseor reduction of the distance of transmission can easily be ascertained.

In thegmodified arrangement of the receiver means according to Fig. 3 electric receivers or microphones e, e are em loyed',

consists in providing an apparatus having two receivers spaced apart with an individual connection from each to an ear of the observer, wherebv there may be createdat the two ears of the observer by reason of the difference in length of the separate paths of the sound from the source to the? nected b electric conduits i, i to the teleobmrvers ears, said receivers bein arphones k serving to conduct the sound to the observers ears. The tele hence k, k are connected by head band a: 'ut are not electrically connected to each other.

Thearranmentaccordingtol ig.4

stantially equal intensity, and .thereafter equalizing the separate paths of the sound from its source to the two ears of the observer by adjusting the apparatus without 3 thereby, that the telephones k, k are conby the instant of arrival of the sound at the nected to the tubes Z, 1. On said tubes 2 Z two cars of the observer may be synthe sleeves v, o are placed which can chronized, thus converting a lateral 1max'ially displaced thereon. The sleeves v, v pression of direction into a central impresare permeated to the receiver tubes w, w, serving to conduct the sound from the telephones I:, k to the observersears.

As the observer cannot ascertain with a single position of the carrier, whether the directipn by measuring the amount of compensation new to cause such equalization.

the method described may Ls further improved by observing by aid of two or more nected to the ears of the observer bv carriers-enclosing an angle betti'een them. se arate paths, which consists in relatively The novel method can of course be carried ad iusting said: paths in the apparatus so as into practice in any medium vthutevcrpro- I i rection from which a sound arrives which 8. time interval between the arrival of sound 106' ranged so as to receive the sound wit sub- 110 'e apparatus according to Fig. changing the obvers orientation where- 116' sion of direction and detennining the actual- 1 a. The method at determining the direxw sound comes from before or from behind, tionef sound by the use of apparatus comprising separated artificial: receivers conto convert a lateral lmpmiOn of direction.

intou central impression of directicnwhilc tion. 4

4. The method of determining the dime tion of sound by the use of apparatus eon. prisin" separated artificial receivers eonnet-ted to the ears of the observer by separate paths which consists in relatively adjusting said pnths'in said apparatus so as to convert a lateral impression of direction into a central impression of direction while maintainin" the receivers in a fixed position, and determining the actual direction by measuring the amount of adjustment necessary to produce such central impressxon.

5. Means for determining the direction of sound which comprises two fixed receivers spaced apart, and separate means for connecting each receiver with an ear of the observer, at least one of said connecting means being adjustable with relation to the other whereby the relative paths of travel of the sound from the receivers to the ears of the observer may be varied 6. Means for de the direction of sound which comprises two fixed receivers spaced apart, and separate mehns for connecting each receiver with an ear of the maintaining the receivers in a fixed push.

observer, at least one of said connecting means being adjustable with relation to the other whereby the relative paths of travel of the sound from the receivers to the ears of the observers may be varied, and means for measurin such adjustment.

7. Means or determining the direction of sound which comprises two fixed receivers spaced apart, each receiver ha a tubular connection adapted to lead to one of the ears of the observer, at least one of said tubular connections being adjustable In testimony whereof we our sig natures. 

